<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div>我是div</div>
    <span>我是span</span>
    <ul>
        <li>我是li</li>
        <li>我是li</li>
        <li>我是li</li>
        <li>我是li</li>
        <li>我是li</li>
    </ul>
    <div class="demo">
        <div class="box">
            <div class="erweima"></div>
        </div>
    </div>
    <script>
        var box = document.querySelector('.box');
        console.dir(box);
        var erweima = document.querySelector('.erweima');
        console.log(erweima.parentNode);

        var ul =document.querySelector('ul');
        console.log( ul.childNodes);
        console.log(ul.children);
        
        
    </script>
</body>

</html>